Brake beam



J. L. MOHUN BRAKE BEAM Feb. 20, 1934.

Filed May 15, 1931 2 Sheets-Sheet l I n 1/6)? for C/0%/2 W050 gaw Feb. 20, 1934. .J. MOHUN 1,947,580

BRAKE BEAM Filed May 15, 1931 2 Sheets-Sheet 2 Iru/en f- Fatented Feb. 20, 1934 iiNl'i'ED STATES BRAKE BEAM John L. Mohun,

Omaha,

Nebn, assignor to Chicago Railway Equipment Company, Chicag'o, 511., a corporation of Illinois Application May 15, 1931. Serial No. 537,520

Claims.

The invention relates to brake beams such as are in general use on railway rolling stock and relates more particularly to brake beams of the truss type in which the ends of compression and tension members are secured to each other either directly or through a thrust block, which may be a part of the brake head or may be formed separately therefrom.

The continued application and release of the 343 brakes tend to produce a weaving action in the tension member adjacent to the brake head, due to the rigidity of the connection, and as a result crystallization and breakage frequently occur.

The object of the present invention is to overcome the disadvantages referred to by providing an anchorage for the tension member on the compression member, whereby the tension member may rock on the outer face of the thrust block and thereby accommodate the weaving forces created by the application and release of the brakes. This object is attained by the structures illustrated in the accompanying drawings, in which- Figure l is a plan of a truss type brake beam embodying one form of the invention.

Figure 2 is an enlarged detail of one end of the beam illustrated in Figure 1.

Figures 3, 5, 6, 7, 9, 11 and 13 are similar details, some of the structures being sectioned in 39 part for clear illustration.

Figure 4 is a detail of a washer device shown in Figure 3.

Figures 8, 10, 12 and 14 are transverse sections on the corresponding section lines of Figures 7, 9, 11, and 13, respectively.

The beam illustrated in Figure 1 includes a compression member 1, a strut 2, and a combined brake head and thrust block 3 having a flat outer surface 4 forming a seat for the device whereby 49 the tension member 5 is anchored to the end of the compression member. The tension member 5 is illustrated as a round rod extending through the thrust block and outwardly therefrom and terminating in a threaded element 6 on which a nut 7 is screwed. A relatively heavy coil spring 8 is compressed between nut '7 and seat 4 and comprises part of an anchorage or seating device which may flex or yield transversely of the axis of the tension member to permit some angular play between the tension member and the compression member to accommodate the weaving forces referred to.

The spring 8 should be stiff enough so as not to deflect under the capacity load required of H the beam to which it is applied, although permitting some deflection under a load exceeding the A. R. A. requirement in order to accommodate the weaving of the brake head on the nut seat. The tension rod will be stiff enough to overcome the resistance of the spring when the brake head and nut tend to rock on each other.

In the structure of Figure 3 the device includes a spring washer 9 (detailed in Figure 4) as distinguished from a coil spring section.

Figure 5 illustrates a nut seat 10 preferably of yielding material which may flex to accommodate the weaving forces or may rock about its thrust block engaging portion 11.

Figure 6 illustrates a somewhat similar seat member 12 which would be of rigid material 0 rocking at 13 on the thrust block and possessing no inherent flexibility.

In each of the above described structures the tension member is an ordinary cylindrical rod threaded on its end portion but the invention con- 5 templates the inclusion of the yielding feature in r the end portion of the rod as Well as in the nut seat structure.

Figures 7 and 8 illustrate a thrust block 14 with the nut 15 seated thereon in the usual man- 0 ner but the tension member 16 has its threaded I end portion 17 split longitudinally as indicated at 18 whereby the weaving motion of the brake head on the beam may be accommodated.

Figures 9 and 10 illustrate a tension rod structure in which the threaded end 19 of the rod 20 is permitted to flex transversely of the rod axis by means of a series of grooves 21 extending inwardly from the outer periphery of the rod.

In the structure of Figures 11 and 12, the end portion of the rod is drilled, as indicated at 22, whereby the end portion is provided with some flexibility transverseiy of the rod axis.

Figures 13 and 14 illustrate a rod 23 which is slotted or bifurcated, as indicated at 24, similar to the arrangement shown in Figures? and 8, but the bifurcation does not extend to the extreme end of the rod.

In all the embodiments of the invention the rod is relieved of the repeated bending of all of its fibers at a point between the sides of the thrust block or located adjacent to the inner face of the thrust block, and the tendency to set up crystallization with resultant breaking of the rod is reduced or eliminated.

The above described structures are intended to illustrate suggested embodiments of the invention without limiting the number of modifications which may be made and I contemplate the structure which come within the scope of the claims.

I claim:

1. In a truss type brake beam, a compression member, a thrust block at the end thereof, a

tension member, and elements on said thrust block and tension member providing interengagement between said thrust block and tension member, said elements including yielding means to accommodate weaving of the brake head relative to the tension member.

2. In a truss type brake beam, a compression member, a thrust block at the end thereof, a tension member, and elements on said thrust block and tension member providing interengagement between said thrust block and tension member, said means including a relatively narrow pivot bearing about which one of said elements may tilt on another of said elements without sliding contact between them.

'3. In a truss type brake beam, a compression member, a thrust block at the end thereof, a tension member, and elements on said thrust block'and tension member providing interengagement between said thrust block and tension mem her, said means consisting of a spring interposed between two of said elements and adapted to under abnormal stresses applied transversely of said tension member.

4(In a truss type brake beam, a compression member, a thrust block at the end thereof, a 1e11- sion member, and elements on said thrust block and tension member providing interengagement between said thrust block and tension member, said means comprising a spring with a pivot portion whereby said spring may compress and also tilt on one of said elements to accommodate relative angularimov'ement between the tension and compression members of the beam,

5. In a truss type 'brake beam, a compression member, a'thrust block at the end thereof, a tension member, and elements on said thrust block and tension member providing interenmember, said means consisting of a reduction in the sectional area of the terminal portion of said tension member whereby said portion may flex transversely of the axis of said member to accommodate relative angular movement of the tension member and compression member of the beam.

6. In a truss type brake beam, a compression member, a thrust block at the end thereof, a tension member including a threaded element, a nut on said threaded element, and a seat element on said thrust block for said nut, at least one of said elements being constructed so as to flex under weaving stresses produced by the application and release of the brakes.

'7. In a truss type brake beam, a compression member, a thrust block at the end thereof, a tension member including a threaded element, a nut on said threaded element, and a seat element on said thrust block for said nut, said seat being constructed to yield at one side of said tension member under uneven pressure from said nut due to application of the brakes.

8. In a truss type brake beam, a compression member, a thrust block at the end thereof, a tension member including a threadedelement, a nut on said threaded element, and a spring washer between said thrust blockand nut.

9. In a truss type brake beam,'a compression member, a thrust block at the end thereof, a tension member including a threaded element, a nut on said threaded element, and a compressible member on said thrustblock forming a yieding seat for said nut.

10. In a truss type brake beam, a compression member, a thrust block at the end thereof, a tension member including a threaded end portion, and a nut on said end portion seated on said thrust block, said end portion being slotted lengthwise to render said portion more flexible, transversely of the axis of said tension member, than the'remainder of the tension member.

JOHN L. MOHUN. 

